pgn@osupyr.mast.ohio-state.edu (Paul G. Nevai) (04/12/89)
This is an oldie: Should an extrenal Mac hard drive be left on 24 hours a day or should it be turned on in the morning and turned off in the evening? I say: turn off My departmental computer committee chairman was adviced to the contrary by his Apple rep. I am inclined to distrust the Apple rep (sorry guys at Apple, I trust you, I just distrust reps) because I feel he just wants to sell more drives to us in the long run. Am I right? Please email your opinion to me (prefer edu address). Paul Nevai pgn@osupyr.mast.ohio-state.edu Department of Mathematics TS1171@ohstvma.BITNET The Ohio State University 73057,172.Compu$erve 231 West Eighteenth Avenue 1-(614)-292-5310.office Columbus, OH 43210, U.S.A. 1-(614)-292-4975.department
mjohnson@Apple.COM (Mark B. Johnson) (04/12/89)
In article <1279@osupyr.mast.ohio-state.edu> pgn@osupyr.mast.ohio-state.edu (Paul G. Nevai) writes: > >Should an extrenal Mac hard drive be left on 24 hours a day or >should it be turned on in the morning and turned off in the >evening? > >I say: turn off > I have always left mine on _all_ the time, but then again I'm not the one who has to pay for repairs (although I have not had any problems). I have seen a lot of drives "lock" and not spin up after having been off for a few hours or days. Mark B. Johnson AppleLink: mjohnson Developer Technical Support domain: mjohnson@Apple.com Apple Computer, Inc. UUCP: {amdahl,decwrl,sun,unisoft}!apple!mjohnson "You gave your life to become the person you are right now. Was it worth it?" - Richard Bach, _One_
kcr%rushforth@Sun.COM (Kevin Rushforth) (04/13/89)
In article <1279@osupyr.mast.ohio-state.edu> pgn@osupyr.mast.ohio-state.edu (Paul G. Nevai) writes: >Should an extrenal Mac hard drive be left on 24 hours a day or >should it be turned on in the morning and turned off in the >evening? What about a home system that is used at various times during the day? Is it better to turn the external hard drive on and off multiple (2 or 3) times a day, or is it better to leave it on all day -- even when no one is at home or when no one plans to use it for several hours? -- Kevin C. Rushforth | "If winning is not important, Sun Microsystems | then commander, why keep score?" | - Lt. Worf ARPA: kcr@sun.com | UUCP: <most-backbone-sites>!sun!kcr |
earleh@eleazar.dartmouth.edu (Earle R. Horton) (04/13/89)
In article <28835@apple.Apple.COM> mjohnson@Apple.COM (Mark B. Johnson) writes: ... >I have always left mine on _all_ the time, but then again I'm not the one >who has to pay for repairs (although I have not had any problems). I have >seen a lot of drives "lock" and not spin up after having been off for a >few hours or days. I have an old Computer Memories drive in an Intel 286-310 which only gets occasional use. Part of starting up this system after not using it for a while is to remove the hard drive, reach into the case with a Popsicle stick, and nudge the flywheel a bit to free it so the disk motor can spin up. If you have occasion to try this trick, do it with the power OFF. Earle R. Horton Graduate Student. Programmer. God to my cats.
flash@cs.qmc.ac.uk (Flash Sheridan) (04/14/89)
I turn mine off several times a day, because it's too loud. You get some *weird* errors if you forget to turn it back on. Once the entire screen shifted an inch to the right.* Shouldn't the SCSI manager be smarter than this? Didn't Ephraim Vishniac post an algorithm to make it so? --- *Not quite, but you know what I mean. -- From: flash@cs.qmc.ac.uk (Flash Sheridan) Reply-To: sheridan@nss.cs.ucl.ac.uk Portal,MacNet: FlashsMom
jez@praxis.co.uk (Jeremy Prior) (04/15/89)
In article <1279@osupyr.mast.ohio-state.edu> pgn@osupyr.mast.ohio-state.edu (Paul G. Nevai) writes: > >Should an extrenal Mac hard drive be left on 24 hours a day or >should it be turned on in the morning and turned off in the >evening? We have an Apple HD20 SC attached to an LaserWriter IIntx, that has not been switched off now for *8 Months*! It has given us no problems at all, despite several power failures. We suffered no ill effects from leaving it on 24 hours a day, 7 days a week. As to whether this has increased or decreased the life of the drive, only time will tell.. -- Jeremy Prior (jez) Telephone: +44 225 444700 Praxis Systems plc Telex: 445848 PRAXIS G 20 Manvers Street, Bath, BA1 1PX, U.K. Fax: +44 225 65205 uunet!mcvax!ukc!praxis!jez jez%praxis.uucp@ukc.ac.uk o //> > //__/<_ /_/
donn@radar.UUCP (Donn S. Fishbein) (04/17/89)
In article <3950@newton.praxis.co.uk> jez@praxis.co.uk (Jeremy Prior) writes: In article <1279@osupyr.mast.ohio-state.edu> pgn@osupyr.mast.ohio-state.edu (Paul G. Nevai) writes: > >Should an extrenal Mac hard drive be left on 24 hours a day or >should it be turned on in the morning and turned off in the >evening? I'm just wondering if anyone actually knows for sure what the MTBF ratings actually mean. Does this refer to the time the drive is on (motor turning), or the time the drive is in use. It seems the MTBF would have to be qualified by the percent activity the drive saw. Anyone know for sure. -- Donn S. Fishbein, MD, PhD CDS Consulting 3473 Golf Club Lane, Nashville, TN 37215 615-385-4755
folta@tove.umd.edu (Wayne Folta) (04/19/89)
I have been told by some engineers that most failures occur when powering on equipment. In the initial current surge and the component warm-up, there is a lot of stress. This is also true with, for instance, lightbulbs, which always seem to fail when you first turn them on. I don't know: 1) whether this is true for motors, such as in a disk; or 2) where the break-even point is between leaving electronics on versus subjecting them to start-up stresses; or 3) where the break-even is between a disk's mechanical components and electronic components. I'll volunteer to be a guinea pig, since I leave my Mac on from the time I come home and first use it, until I go to bed(as much as 8 hours), even if I will be using it only intermittently during the evening. Wayne Folta (folta@tove.umd.edu 128.8.128.42)
alexis@ccnysci.UUCP (Alexis Rosen) (04/23/89)
Draw your own conclusions:
Drive: Quantum 280 (5.25" H/H 80MB, used by Apple and many other companies)
Sample Size: 37 units, 14 of which have been left on since they were installed.
Installed: 15-18 months ago
Failures: 5, all of which were motor/spindle failures, all on the units which
were NOT left on.
The way I see it, only a fool would turn their drives on and off every day.
Which makes me out to be pretty dumb- my personal drive was the second to
fail. :-(
Now, I don't turn off my CDC drive, unless I'm going to be gone for more than
2 days. It hasn't been off in about three months, except for a few minutes to
install the Orchid Cache Board.
---
Alexis Rosen
alexis@ccnysci.{uucp,bitnet}
alexis@rascal.ics.utexas.edu (last resort)